This application is a continuation-in-part of application Ser. No. 11/872,163 filed Oct. 15, 2007 and entitled “Stem-Mounted Tire Inflation Pressure Regulator” (the disclosure of which is incorporated by reference).
The present invention relates to threaded connections, and more particularly to locking threaded connections that prohibit or reduce unintended relative rotational movement in at least one direction.
Threaded fasteners and connections are well known and widely used in manufacturing and other applications. Typically, a male portion of the fastener is externally threaded, and a female portion of the fastener is internally threaded. The two portions threadedly interfit, and relative rotational movement results in relative axial movement of at least one of the portions. The axial movement typically is associated with tightening and loosening the fastener.
One issue associated with threaded fasteners and connections is unintended and undesired relative movement, for example resulting in loosening of the fastener. Consequently, a variety of fastener modifications have been developed for preventing or reducing such movement. These include without limitation cotter pins, lock washers, and friction-creating materials, such as Nylon. Another technique is the physical deformation of one or both portions of the threaded connection. Unfortunately, there are various problems with each of these modifications. Cotter pins add cost and complexity and are inappropriate for most threaded applications. Lock washers have been proven to be ineffective in applications where there is vibration. Locking patches and distorted threads introduce prevailing torque during both installation and removal. This can slow assembly and disassembly, and the prevailing torque reduces the torque transmitted to the bolt. Since prevailing torque varies with the number of times the fastener is reused, and often with temperature, a lower maximum torque must be specified with prevailing torque locking fasteners to prevent the bolt from being overstressed.